Scintillation cameras are well known in the art, and are used for medical diagnostics. A patient is injected, or ingests or inhales a small quantity of a radioactive isotope. Whose emission photons are detected by a scintillation medium in the camera. The scintillation is commonly a sodium iodide crystal, BGO or other, which emits a small flash or scintillation of light, in response to stimulating radiation. The intensity of the scintillation is proportional, (but not linearly) to the energy of the stimulating gamma photon.
As known in the prior art, the depth of interaction of the scintillation in the crystal is proportional to the energy of the gamma photons. As a prior art this fact prevents Anger based gamma cameras from having linear positional response for different energies. In order to produce a diagnostic medical image, scintillations having an energy which corresponds to the energy of the decay gamma photons of the radioactive isotope are detected and the intensity each scintillation in the crystal (or crystals for multicrystal cameras) is measured.
Then, the position of the scintillation calculated, and the calculated position is corrected for the scintillation. Similarly the energy is calculated and corrected. All the calculations are based on the energy intensity values of at least three light detectors (n-tuple) coupled to the surface of the scintillation medium and surrounding the point of scintillation.